Silent Night, Deadly Night (1984)

Storyline:

Silent Night, Deadly Night (1984) After seeing his parents murdered in front of him a young bit spends most of his life in an orphanage where he is abused by the mother superior when he turns into a teenager he gets a job as a department store santa and when he sees two people having sex in the store he gets flashbacks when his parents and when he can't take it anymore he turns into a santa serial killer.